The UV-B Monitoring and Research Program operates a network of solar irradiance monitoring stations, throughout the United States. For more detail about our instrumentation, and locations please select Network.

The data is divided into primary data, derived data products, UV climatology products, and instrument characteristics.
For detailed information about our calibration please select Data Processing.

Primary Data:

Irradiance is a measurement of solar power and is defined as the rate at which solar energy falls onto a surface.

  • Visible irradiance (watts per square meter per nanometer) at nominal 415, 500, 615, 673, 870, and 940 nm wavelengths
  • UV irradiance (watts per square meter per nanometer) at nominal 300, 305, 311, 317, 325, 332, and 368 nm wavelengths
  • Erythemal weighted irradiance (watts per square meter) determined from broadband measurements between 280 to 320 nm wavelengths
  • Photosynthetically Active Radiation between 400 to 700 nm wavelengths. The measurement is of Photosynthetic Photon Flux Density (PPFD), which has units of quanta (photons) per unit time per unit surface area, which for this sensor is in micromoles per second per square meter.
Our derived data products are:
  • Daily and Hourly Sums represent an integration over time. By summing the readings over the number of seconds in the measurement period, the units of radiant power are converted to radiant energy and are useful for studying effects related to exposure.
  • Synthetic Spectra is an estimation of the continuous spectrum of UV spectral irradiance incident at the surface.
  • Instantaneous Optical Depths total or aerosol + cloud is determined for a time series of Langley-generated voltage intercepts for morning periods.
Our UV climatology products are:
  • UV Irradiance provides statistics at 305, 314, 324, and 380 nm wavelengths for a selected region within the United States.
  • Spatio-Temporal Distribution of UV-B radiation across the United States as downloadable data sets.

A site’s data may be viewed as graphs for a maximum time frame of two months using the Interactive Data Download This will also allow you to download the data for any time period. However, UVMRP also provides generated data sets for both our primary data and products organized by site and/or date which can be accessed using the Data Sets Download. For special data requests please send an email to nreluvb-webmaster@colostate.edu or call 970-491-3600. The message should include the location, data type, and contact information.

All data are downloaded in CSV format with a header describing the type of data and data format. Our nighttime data are set to -9999. Data that are not currently available or associated with instrument errors are set to -9998.